: Surge Tank Design

12-11-05, 03:28 PM
OPerating a 94 N* Concours, 164 K. outstanding automobile!!

Can someone advise what the interior design of Tank is like? I see the overflow pipe near radiator cap and a small hose on top of tank that leads under the engine valley cover to where I don't know. Appears too small for coolant it Must be air bleeder for system. How does coolant actually get out of tank and where does it enter the cooling system. ? Concern is about plugged lines and tank.

I am having some over heating issues and have spent a lot of time on the forum threads. Promise to do the right thing for my lovely N* . Drive any auto over a 100K and it becomes a hobby.

12-11-05, 08:42 PM
A common cause of overheating is the purge line. That is the 3/8" line at the top that runs under the cover. It goes to the warter pump. With the engine running, remove that line at the surge tank to be sure it is flowing. If it is, quickly plug it back on. If it is not, then you need to blow it out or remove it and clear the obstruction either in the line or where it connects to the pump.

If cooling system suppliment (sealant tabs) were put in the surge tank, they tend to settle at the bottom and plug the return line as there is not a lot of flow in the tank. I think that line is at the bottom but am not positive. That would be the logical place for it.

Also check the water pump belt tensioner to be sure it moves freely and is not rusted in place. just put a 1/4" breaker bar in the square lug on the backside and excersise it. A little oil on the fulcrum would not hurt.